/* nag_stable_sort (m01ctc) Example Program.
 *
 * Copyright 1990 Numerical Algorithms Group.
 *
 * Mark 2 revised, 1992.
 * Mark 7 revised, 2001.
 * Mark 8 revised, 2004.
 *
 */

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nag_stddef.h>
#include <nagm01.h>


#ifdef __cplusplus
extern "C"
{
#endif
  static Integer NAG_CALL compare(const Nag_Pointer a, const Nag_Pointer b)
  {
    double x = *((const double *)a);
    double y = *((const double *)b);
    return (x<y ? -1 : (x==y ? 0 : 1));
  }
#ifdef __cplusplus
}
#endif

#define VEC(I,J) vec[(I)*tdvec + J]
int main(void)
{
  Integer exit_status=0, i, j, k, m, n, tdvec;
  NagError fail;
  double *vec=0;

  INIT_FAIL(fail);

  /* Skip heading in data file */
  Vscanf("%*[^\n]");
  Vprintf("nag_stable_sort (m01ctc) Example Program Results\n");
  Vscanf("%ld%ld%ld", &m, &n, &k);
  if (m>=0 && n>=0 && k>=0 && k<=n)
    {
      if ( !( vec = NAG_ALLOC(m*n, double)) )
        {
          Vprintf("Allocation failure\n");
          exit_status = -1;
          goto END;
        }
      tdvec = n;
    }
  else
    {
      Vprintf("Invalid m or n or k.\n");
      exit_status = 1;
      return exit_status;
    }
  for (i=0; i<m; ++i)
    for (j=0; j<n; ++j)
      Vscanf("%lf",&VEC(i,j));
  /* nag_stable_sort (m01ctc).
   * Stable sort of set of values of arbitrary data type
   */
  nag_stable_sort((Pointer) &VEC(0,k-1), (size_t) m, sizeof(double),
                  (ptrdiff_t)(n*sizeof(double)), compare,  Nag_Ascending,
                  &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_stable_sort (m01ctc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  Vprintf("\nMatrix with column %ld sorted\n", k);
  for (i=0; i<m; ++i)
    {
      for (j=0; j<n; ++j)
        Vprintf(" %7.1f ", VEC(i,j));
      Vprintf("\n");
    }
 END:
  if (vec) NAG_FREE(vec);
  return exit_status;

}